initial

joplin notion extension/Web Development/Javascript/regular expressions.md

@@ -0,0 +1,19 @@
+regular expressions
+
+- dot character in regex dont include newline character so use this `[\s\S]` instead of `.`.
+  eg: `const questionreg = /\.gpt\s+([\s\S]*)/;`
+- variables in regex
+  ```js
+	// variable == 'REGEX'
+	
+	// to escape special characters like +,.,etc in variable string
+	function escapeRegExp(string) {
+	  return string.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+	}
+
+	const variable = <VALUE>
+	
+	let re = new RegExp(String.raw`\s${variable}\s`, "g");
+	```
+- word boundary
+  to search by word `/\bword\b/` instead of `/word/`